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Aug. 25, 1953 R. T. SPENCER ADJUSTABLE WEIGHT-BIASED RELIEE VALVE Filed se 1;. '22, 1 948 7 6 Sheets-Sheet 3 Ila" //a //9 1953 R. T. SPENCER 2,649,774

' ADJUSTABLE WEIGHT-BIASED RELIEF VALVE Filed Sept.- 22, 1948 6 Sheets-Sheet 4 R. T. SPENCER ADJUSTABLE WEIGHT-BIASED RELIEF VALVE Aug. 25, 1953 6 Sheets-Sheet 5 Filed Sept. 22, 1948 WV uqzzys Aug. 25, 1953 T. SPENCER ADJUSTABLE WEIGHT-BIASED RELIEF VALVE Filed Sept. 22, 1948 dizzy;

amen

Patented Aug. 25 1953;

UN ITED STATES ENT QF FICE.

Riilaiid spencen- Rome; Y.-, alssig noi to Revere" Copper and Brass Incorporated, Rome, N. Y.-, a-corporation of Maryland Application September 22, 1948', serial No. 50,583

My invention relates'to pressure cookers;- p

The invention has among its objects improved means for controliing and selectivelyregulating the pressure within a pressure cooker. e

The above and other dbjects of the invention will be best understood from the following description when read in the light of the accompanying drawings of several specific embodi ments of the invention selected for illustrative purposes, while the scope of the inventionwill be more particularly pointed out in the app nded claims.

In the drawings Fig. 1 is a front elevation of a pressure cooker according to the invention, with parts in section;

Fig. 2 is a plan of the pressure cooker ac'cerding to Fig. 1 I

Fig. 3 is a plan of p a fragment of the ressure cooker according to Figs. 1 and 2 on anenlarged scale, with parts in section;

Fig. 4 is a section on the line 4-4 of Fig. 3;

Fig. 4 illustrates a detail Figs. 5 and 6 are, respectively, sections on the lines 5-5 and 6-6 of Fig. 4;

Figs. 7 and 8 are, respectively, sections on the lines 1-! and 8"-'-8' of Fig. 3; with parts omitted Figs-9, 10 and 11 are" sections corresponding to Fig. 4, with the parts in different operative positions; 7 1

Figs. 12 and 13 are; respectively, sections on the lines I2-l2 and Iii-13 of Fig. 9, with parts omitted;

Fig. 14 is an elevation, with parts in section,

of a fragment of a pressure cooker having a modified form of controlling valve mechanism shown in its operative position;

Fig. 15 is an'elevation according to Fig. 14,;

with the parts in a different operative position;

Fig. 16 is an isometric view of a shield employed in the pressure cooker according to Figs.

14 and 15'; Fig. 17 is a plan of the upper weight of the controlling valve according to Figs. 1 to 16;v

( Fig. 18 is a side elevation of the weight ac cording to Fig. 17;

, Fig. 19 is an end elevation, as viewed from the right, of the weight according to Figs. 17 and 18;.

Fig. 20 is, a plan of the intermediate weight according to Figs. 1 to 16;

Fig. 21 is a side elevation of the weight ace" cording to Fig. 20;

Fig. 22 is a bottom view of the lower weight according to Figs. 1 to 16'; and

Fig. 23 is a side elevation of the weight ac cording to Fig. 22..

Aside from the pressure controlling meshes-'- n-ism, the pressure cooker illustrated is generally like those'shown by co-pending application-s of William A. Welden, Serial Number 677,043; filed June" 15, 1946; now Patent- No. 2,614,723; and Serial Number 695,128, filed September 6, 1946-. new Patent No. 2,614,725, while the pressure centre ling mechanism is generally likethat shown by (co-pending application of Glenn Wyman,-Serial Number2-6,862,- filed May 13, 1948; now Paterit No. 2,614,724, all three patents issuing on October 21, 1952, the present invention constitut ing an improvement on the last.

As illustrated, the pressure cooker comprises a container, preferably formed of sheet metal such as stainless steel, having a bottom wall I and cylindrical side walls 3. Adjacent their .upper edges the side wall are formed to present an outwardly flared frusto-conical portion .6 ex-'- tending entirely about said walls, At its upper edge this frusto-conical portion is formed to pre sent a narrow inwardly turned lip 1 extending about said portion for approximately At the side of the frusto conical portion diametri .cally opposite the lip I said portion is formed with a narrow outwardly projecting downwardly turned lip 9 of shorter angular extent than the 11p 1. Carried: by the container is a radially projecting handle l3 having a base portion l6 se cured to the cylindrical walls of the container, preferably by welding, this handle being provid ed with the handle grips l1.

As shown, the cover, which also is formed of sheet metal, preferably stainless steel, is shaped to present a dome-like central portion l9 surrounded by'a flattened relatively narrow annular flange 2|. Integral with the outer peripheral edge of this flange is an inwardly turned downwardly extending frusto-conical flange 23 ex tending entirely about the cover. Carried by the cover at its under side is a gasket ring 25 of greater height than the flange 23, this ring being formed of flexible resilient material such as synthetic rubber, and being shaped to fit into the space between the flanges 2| and 23 and to pro vide a lower portion 21 which projects radially beyond the outer side of the flange 23 at its lower edge so-as to bear .uninterruptedly against the inner wall of the frusto conical portion 6 of the container when the cover is assembled with the latter.

As shown, the cover is provided with a radially projecting handle 29 provided with the handle grips 31. This handle is provided with a base portion 33 which and the adjacent portion of the body of the handle conform to the upper sides of the dome-shaped portion I9 and annular flange 2| of the cover to which they are secured preferably by welding. Secured to the under side of the handle 29, also preferably by welding, is the base 35 of a strip-like member which, at its end adjacent the cover, is provided with a downturned portion 31, which latter, at its lower end, is upwardly turned to form a hook 39.

When the parts are in the position shown by the drawings the cover is removably retained on the container by the container lip 1 positioned above the cover flange 2| and by the container lip 9 positioned above the cover hook 39. When the cover is initially placed on the container a clearance 43 exists between the container lip 1 and cover flange 2|, and an equal clearance l5 between the container lip 9 and cover hook 39', the projecting portion 21 of the gasket. ring 25. bearing against the frusto-conical container portion 6 so as to seal the joint between the cover and container and thus permit pressure to build up in the cooker. When the pressure builds up the cover rises to take up the clearances 43 and 45, the gasket ring because of its resiliency and the pressure in the cooker remaining in contact with the frusto-conical container portion 6 so that at all times the gasket renders the joint between the cover and the container steam-tight.

,As shown, the base portion 33 of the handle 29 and the cover portion I9 immediately below said base portion are jointly formed to provide a perforation 41 (Fig. 4) through which extends the shank portion 49 of a plug having a head 5| below the cover. Surrounding the shank, and positioned between the head and the under side of the cover, is a resilient gasket washer 53. The upper projecting end of the plug is screwthreaded, and is received in a nut 55 resting against the upper side of the base portion 33 of the handle 29. This nut serves to secure the plug in assembled relation with the other parts and to compress the gasket washer 53 for rendering the joint between the plug and the cover fluid-tight. The plug is further provided with a longitudinal through bore 51 serving as a vent passage for the cover.

As illustrated, the handle 29 adjacent its base portion 33 is shown as struck up at opposite sides to form upwardly projecting ears 59 (Figs. 3 to 8). Carried by these ears above the bore or vent passage 51 are shown an upper weight 6|, an intermediate weight 63 and a lower weight 65. These weights are best illustrated in Figs. 17 and 23, and the manner of assembling them with each other and the ears by Figs. 3 to 6. The weight 6| as illustrated by these figures has a disk-like body formed with a lateral projection 61 from opposite sides of which downwardly extends a pair of spaced ears 69. These ears 69 are received between the pair of cars 59 on the handle 29, on which ears 59 they are pivotally mounted by pins 1| (Fig. 3) received in perforations 13 in said ears 59, the pins having screw-threaded shanks 15 received in screwthreaded openings 11 in the ears 69. j

The intermediate-weight 63, as shown, is substantially in the form of a flat disk, cut away at one side as indicated at 19 (Fig. 20), to form a tang 8|, the upper and lower sides 83 of this tang converging toward each other as theyapproa'ch the free end of the tang, as indicated in Fig. 21, to permit swinging of the weight relative.

to the upper and lower weights when the parts are in the assembled relation shown by Fig.4.

The tang 8| of the weight 63 is received between the ears 69 of the weight BI and is provided with a through perforation in alignment with the perforations 81 formed in the ears 69 of the weight 6|. Through these perforations extends a pin 89 (Figs. 4 and 6) which pivotally secures the weight 63 to the weight 6|.

. The lower weight 65in outline is identical with the weight 63, as will be clear from a comparison of Figs. 20' and 22, except that the tang 9| of the weight 65 is not tapered. This tang 9|, as shown, is provided with a perforation 93 which, in the assembled device shown by Figs. 4 and 6, is in alignment with perforations 95 formed in the ears 69 of the weight 6|. Through these aligned perforations extends a pin 91 for pivotally securing the weight 65 to the weight 6|. The lower weight 65 is shown as provided with a perforation 99 (Figs. 4, 22 and 23) which at one end is formed with an enlarged diameter portion IIII forming a shallow recess for receiving a washer-like member I93 (Figs. 4 and 4 pressed into said recess. Loosely extending through the opening I65 of this washer-like member is the upwardly projecting shank I91 of a frusto-conical valve I99 adapted to seat on the valve seat presented by the upper peripheral edge of the bore 51 presenting the vent passage. At the under side of the member I93 the valve adjacent its base is formed with an annular radially extending flange III adapted to seat on the under side of said member for forcing the valve against its seat when the parts are in the position shown by Figs. 9, 10 and 11. At the upper side of the member I03 the shank I91 is formed with a reduced diameter portion II3 which receives a washer |I5 resting on the shoulder ||1 formed by this reduced diameter portion. At the upper side of the washer II5 the reduced diameter portion of the shank is riveted over, as indicated at H9, for securing the washer II5 to the shank of thevalve. This washer acts to retain the valve in assembled relation with the member I93. The loose flt of the shank of the valve in the opening I05 permits the valve to move laterally relative to the lower weight 65 so that the valve will accurately seat on the valve seat.

As shown, the upper weight 6| is formed with a screw-threaded opening I2I (Figs. 4, 17, 18 and 19) into which is screw threaded a screw I23, the screw freely passing downwardly through openings I25 and I21, formed in the weights 63 and 85, respectively, in alignment with the screwthreaded opening I2 I. At its lower end the screw is adapted to bear on the upper side of the base portion 33 of the handle 29 so that by rotating the screw the upper weight 6| may be lifted relative to the cover of the pressure cooker.

Atthe opposite side of the valve I99 from the screw I23 the upper weight 6| is formed with a screw-threaded opening I29 into which is fixedly screw-threaded a. downwardly projecting pin |3I (Fig. 4) This pin is formed with progressively enlarged diameter portions I33 and I35, the portion I33extending through an opening I31 in the intermediate weight 63 and the portion I35 extending through an opening. I39 in the lower weight 65. At its lower end the pin is formed with azhead MI belowthe lower weight 65. The enlarged diameter portion I35 'of the pin forms with the smaller diameter portion I33'thereof an annular shoulder I43 of greater outer diameter than the diameter of the opening I31 in the intermediate weight 63, while the head. |4| of the pin ef 'grater outside diameter thari the diameter of the opening I39 the lower weight 65.

The screw I23 at its upper end projects above the upper weigh-t GI. This Diojcthig portion of the screw is integrally formed with a collar I45. The portion M1 of the screw above the collar is screw-threaded, on which portion is screwth-read'ed a bushing I 49 about which is fixedly m'olde'd a knob' I! for turning the screw. Clamped against the collar I45 by the bushing I49 and knob I5'I is the base portion I5? of a spring arm I55 (Figs. 2, 3 and 9) the outer endI5-1 of which extends over theapper side of the upper weight BI. This spring arm is provided with a perforation I59 (Fig.- 13) so that the portion I 41 of the screw will pass through it. For securing the arm against rotation relative to the sc'rew the collar I45 is provided with a perforation WI (Fig. 12) in alignment with a perforation I53 (Fig. 13) in the spring arm, and through these perforations is passed" a rivet I55 (Fig. 9'). On its upper surface the weight BI is formed with spaced recesses I61, I59, Ill and I13 (Figs. 3 and 17) which are connected by shallow arcuate grooves I15, while the spring arm is struck up to form a downwardly extending downwardly tapering projection I11 (Fig. 9) adapted to be resiliently received in these recesses and grooves. The recesses I61, I69, Ill and I13 serve to locate the screw in different rotative positions relativeto the upper weight 6| by reason of the projection I11 on the spring arm snapping into them when moved into registry with them and automatically moving out of them when the arm is turned by the operator. The lowerend of the projection I11 is-adapted to bear on the bottoms of the grooves I15 and thus keep the under side of the spring arm from contacting with the upper surface of the weight 6!. Further, these grooves, serve to obscure the effect of the projection I11 in respect to its scratching the upper surface of the weight BI. Conveniently the weight 6| is provided with the upwardly projecting stop pins I18 which co operate with the spring arm I55 to limit its extent of motion in opposite directions.

When the parts are in the position shown by Fig. 11 the three weights 5|, 63 and 65 act conjointly to hold the valve I09 against its seat, the lower end of the screw I23 under these conditions being out of contact with the portion of the cover aiforded by the base portion- 33 ofthe cover handle 29. To move the screw into this position the knob I5I is rotated to cause the projection I11 on the spring arm I55 to register with and snap into therecess H51 on the upper weight SI. The position of the weights shown by Fig. 11 represents the maximum pressure that may be main tained in the pressure cooker, say a pressureo'f 15 pounds as indicated by the ordinal 15 applied to the upper side of the upper weight 6| as shown in Figs. 2 and 3.

If the knob is turned in a counter clockwise direction, as viewed in Fig. 2, to cause the projection I 11 of the spring arm to snap into the recess I69, the lower end of the screw will be caused to contact with the upper side of the cover portion 33 to swing the upper weight upward into the position shown by Fig. 10, under which conditions the valve will be held to its seat only bythe weights 53 and 65. This may correspond toa pressure of 10 pounds to be maintained in the pressure cooker, as indicated by the ordinal 10 applied to the upper surface of the weight 6| adjacent the recess I69.

If the spring arm is moved farther in a counter:

eioeiivasgerrectiem to cause the iireje(st-ion in of the sp'rmgerm tosses into the-recess III, the upper weight 51 will be lifted farthe to cause the shoulder I43 on the pin I'3I to engage the under side of the weight 63 also to" lift it ass own by Fig. 9'. Under" these conditions the valve is pressed against its seat only by the lower weight 65; which corresponds, for example,- to the mainta-ihi'n-g' ofa' pressure inf the pressure" cooker" or but e pounds as-indicatedby the 0151 nal- 5 applied to the upper sideof the upper'weight 5| aaiaaefit thereeess I1I g If the spit gf arm is turned sun farther a counter -clockwise di-reetion, to oause the pro ection- I11 (if that arm to snap into the recess I13, the head? I41 of the pin I 3fI will engage the finder side of the lowerweight 65' also to lift it as shown in Fig. i,- su'oh lifting of the weight 65 raising the valve I 09' from" its seat so that no pressure will be maintained in the pressure cooker, as indicated by the ordinal 0 applied to the upper-side of the upper weight 61 adjacent the recess I13 as shown in Fig. 17. A,

It will be observed that by the construction above described the weights are swingai-bly mounted at one side: of the vent opening, ascrew being positioned between the vent opening and pivotal mounting of the weights for lifting the upper weight, while the pin I3I provides a lost motion coupling between the weights effective to raise the weight 53 and then the weight 55' as the weight BI is moved upward by the screw. It will also be observed that the pivoted lower weight forms a lever which supports the valve, the rip-- ward motion of the valve being multiplied lie-'- cause of this lever in respect to the distance the screw is moved longitudinally relative to the weight 6|. Only a relatively slight movement need be imparted to the weight BI by meansof the screw, satisfactory results being obtained with ascrew having 10' threads to the men with the parallel axes of the screw and valve spaced apart 0.5 inch, as viewed in Fig. 11,- and the other parts proportioned relative to such dimension as shown in the drawings. It will also be observed that only the upper end portion of the screw-thread of the screw illustrated plays any active part in lifting and lowering the weight 61 this screw-thread and the Cooperating internal screw-threads of the weight 5i in effect forming a cam and cam-r01: lower which act to lift or lower the weight when the screw is rotated.

For preventing the steam escaping from the vent openingbeing projected over the handle" of the cooker cover there is preferably provided a shield I19 (Figs. 1 to 5 and 8); This shield bridges the space between the two ears 59 and acts substantially to close the space between the under side of the lower weight 65 and the top' of the: cover. The shield ateach end is provided with portions I8I which engage the outer sides of the ears 59, these portions I81 at their free ends adjacent their lower edges having inturned tabs I83 which en age the edges or the ears adjacent the weights,- and being formed with perforations I85 which receive the projecting ends of the pins 1|, so that the shield will be securely held in as sembled relation with the ears.

For reasons of safety it is important that care be taken by the operator to insure that the cooker is completely vented before attempting to remove the cover. Such complete venting may of course be secured in the cooker heretofore described by turning the screw to bring the spring aifn I55 into the 0 position. However, if desired, the parts may be designed to permit the weights to be moved into the position shown by Fig. 15 for completely venting the cooker, the construction under such circumstances being identical with that heretofore described, except that the upper edge of the shield I87 then employed is lower than the shield I19 heretofore described as will be clear from a comparison of Figs. 4 and 14. In the position shown by Fig. 15 the three weights have been swung upward as a unit to move their centers of gravity past the vertical and cause the weight 6| to rest upon the top of the shield I81 for supporting the unit in that position, the normal position of the weights being that shown in Fig. 14. If desired, with the construction shown by Figs. 14 and 15 the zero position of the spring arm may be omitted by omitting the recess H3 in the upper surface of the weight BI and suitably positioning the lower stop pin H8 as viewed in Fig. 3.

It will be understood that within the scope of the appended claims wide deviations may be made from the forms of the invention described without departing from the spirit of the invention.

I claim:

1. A vent valve adapted to be urged toward open position by pressure of the fluid to be vented and a weight for urging said valve toward closed position in opposition to such pressure, an auxiliary weight adapted to be supported by the first mentioned weight for augmenting the valve closing force exerted by the first mentioned weight, and manually operated mechanism comprising a part rotatably carried by the auxiliary weight and adapted operatively to bear against a relatively fixed part, said auxiliary weight and part carrying cooperating cam and cam-follower portions for adapting rotation of said part to cause lowering and lifting of said auxiliary weight relative to said fixed part into and out of a position in which it is supported by the other weight whereby both weights or only the said other weight may control the vent opening.

2. A vent valve adapted to be urged toward open position by pressure of the fluid to be vented and a weight for urging said valve toward closed position in opposition to'such pressure, an auxiliary weight adapted to be supported by the first mentioned weight for augmenting the valve closing force exerted by the first mentioned weight, and manually operated mechanism comprising a part rotatably carried by the auxiliary weight and adapted operatively to bear against a relatively fixed part, said auxiliary weight and part carrying cooperating cam and cam-follower portions for adapting rotation of said part to cause lowering and lifting of said auxiliary weight relative to said fixed part into and out of a position in which it is supported by the other weight whereby both weights or only the said other weight may control the vent opening, there being a lost-motion connection between said weights for causing lifting of said auxiliary weight by said part to a predetermined degree to lift the said other weight so that the vent opening is controlled byneither.

3. In a device of the character described a body having a vent opening, means for controlling said vent opening comprising a valve and a pair of weights for urging said valve toward its seat, which weights are swingably mounted on said body at one side of said vent opening in superimposed relation, and a manually operated screw screw-threadedly carried by the upper weight and extending through an opening in the lower weight adapted to bear at its lower end operatively against said body between said vent opening and g the swingable mountings of said weights, whereby said screw may be rotated to lower said upper weight to cause it to be supported by the lower weight so that both control said vent opening, or to raise said upper weight to cause it to be supported by said screw so that only said lower weight controls said vent opening.

l. In a device of the character described a body having a vent opening, means for controlling said vent opening comprising a valve and a pair of weights for urging said valve toward its seat, which weights are swingably mounted on said body at one side of said vent opening in superimposed relation, a manually operated screw screwthreadedly carried by the upper weight and extending through an opening in the lower weight adapted to bear at its lower end operatively against said body between said vent opening and the swingable mountings of said weights, and a part carried by the upper weight adapted to engage and lift the lower weight upon predetermined upward movement of the former, whereby said screw may be rotated to lower said upper weight to cause it to be supported by the lower weight so that both control said vent opening, or to raise said lower weight to cause it to be supported by said screw so that only said lower weight controls said vent opening, or further to raise said upper weight to cause both to be supported by said screw so that neither controls said vent opening.

5. In a device of the character described a body having a vent opening, means for controlling said vent opening comprising a valve and at least three weights for urging said valve toward its seat, means mounting said weights on said body at one side of said vent opening in superimposed relation for vertical swinging, a first part rotatably carried by the upper weight extending through openings in the weights below it and adapted to bear at its lower end operatively against said body, said first part and upper weight having cooperating cam and. cam-follower portions for causing rotation of said part when it so bears to swing said upper weight upwardly for lifting it relative to the body, a second part carried by the upper weight having spaced abutment surfaces for cooperating with the weight below said upper weight for causing the weights below said upper weight, starting with the uppermost thereof, to be progressively swung upwardly for lifting them when said upper weight is so swung for lifting it through predetermined distances, whereby said first part may be rotated to cause one or more of the weights above the lower weight to be supported by the latter so that the vent opening is controlled by a plurality of said weights, or to cause all the weights except the lower weight to be supported by said first part so that only the lower weight controls said vent opening.

6. The combination according to claim 4 in which the said part carried by theupper weight connects both weights so that they may be swung as a unit together with the screw into a position in which the center of gravity of such unit is at the side of the mounting of the unit opposite the vent opening.

7. In a device of the character described a body having a vent opening, a vent valve for said opening adapted to be urged into open positionby the pressure of the fluid to be vented, a weight for urging said valve toward closed position in opposition to such pressure, an auxiliary weight, means operatively mounting said auxiliary weight on said body for vertical swinging, the two weights having cooperating portions for supporting the auxiliary weight on the first mentioned weight for augmenting the valve closing .forceof said first mentioned weight, and manually operated mechanism .cooperating with 'said .bodyand auxiliary weight for swinging said auxiliary weight relative to said body and first mentioned weight forraising and lowering said auxiliary weight to place such portions of the .two weights selectively into and out of such coeperation.

.8. The .combination according to claim :7 in which means are provided for also operatively .mounting the first mentioned weight of that claim on the body for vertical swinging, the manually operated mechanism comprising means cooperating with both weights and said body :forswinging the auxiliary weight relative to said body and first mentioned weight for raising and lowering said auxiliary weight to place the cooperatingportionsof the two weights selectively into and out of cooperation and for swinging said first mentioned weight upwardly relative to said body when the auxiliary weight is raised a predetermined extent.

9. In a device of the .character described a body having a vent opening, means for controlling said vent opening comprising a valve and at least three weights for urging said valve toward its seat, means mounting said weights on said body for vertical swinging in superimposed relation so that the lowermost is adapted to support those above it, lost motion couplings between at least all the weights except the lowermost for causing upward swinging of the uppermost weight into successive positions progressively to take up the lost motions of such couplings and progressively lift the weights so coupled, and a manually operated lifting device for swinging the uppermost weight for lifting it relative to said body into such successive positions, whereby only the lowermost weight or it and one or more of the weights above it may be caused to control said vent opening.

10. In a device of the character described a body having a vent opening, means for controlling said vent opening comprising a valve and at least three weights for urging said valve toward its seat, means mounting said weights on said body for vertical swinging in superimposed relation so that the lowermost is adapted to support those above it, lost motion couplings between all said weights for causing upward swinging of the uppermost weight into successive positions progressively to take up the lost motions of said couplings and progressively lift all the weights beneath it, and a manually operated lifting device for swinging the uppermost weight for lifting it relative to said body into such successive positions, whereby any number of the weights or none of them may be caused to control said vent opening.

11. In a device of the character described a body having a vent opening, means for controlling said vent opening comprising a valve and at least three weights for urging said valve toward its seat, means mounting said weights on said body for vertical movement in superimposed relation so that the lowermost is adapted to support those above it, lost motion couplings between at least all the weights except the lowermost for causing upward movement of the uppermost weight into successive positions progressively to take up the lost motions of such 510 couplings and progressively lift the weights so coupled, .and .a manually operated lifting device carried by the uppermost weight and cooperating with said body for lifting said uppermost weight relative to said body into such successive positions, whereby only the lowermost weight or it and one or more of the weights above it may be caused to control said vent opening.

' 12. In a device of the character described a body having a vent opening, means for controlling said vent opening comprising a valve and at least three weights for urging said valve toward its seat, means mounting said weights on said body for vertical movement in superimposed relation sothat the lowermost is adapted tosupport those above it, lost motion couplings between all said weights for causing upward movement of the uppermost weight into successive positions progressively to take up the lost motions of said'c'ouplings and progressively hit all the weights beneath it, and a manually operated lifting device carried by the uppermost weight and cooperating with said body for lifting said uppermost weight relative to said body into such successive positions, whereby any number; of the weights or none of them may be caused to control said vent opening.

13. A pressure vessel provided with a vent opening, a valve for said opening adapted to be urged toward open position by pressure within the vessel, a swingable weight for urging said valve toward closed position, which weight comprises a first weight part which is swingably carried by said vessel and a second weight part which is swingably carried by said first weight part, said weight parts being positioned in superimposed relation, and manually operated mechanism for selectively causing the uppermost of said two superimposed weight parts to be supported by the lowermost whereby both are adapted to urge the Valve toward closed position for maintaining a predetermined pressure within the vessel or the uppermost to be supported by the vessel whereby the lowermost only of the two is adapted to so urge said valve for maintaining a lower predetermined pressure within the vessel.

14. A pressure vessel provided with a vent opening, a valve for said opening adapted to be urged toward open position by pressure within the vessel, a swingable weight for urging said valve toward closed position, which weight comprises a first weight part which is swingably carried by said vessel and a second weight positioned below said first weight part and swingably carried thereby, and manually operated mechanism for selectively causing said first weight part to be supported by said second weight part whereby both are adapted to urge the valve toward closed position for maintaining a predetermined pressure within the vessel or the first weight part to be supported by the vessel whereby said second weight part urges said valve toward closed position without the first weight part so urging it for maintaining a lower predetermined pressure within the vessel.

15. A pressure vessel according to claim 13 in which the manually operated mechanism comprises a part carried by the uppermost of the two weight parts adapted to be selectively adjusted into contact with the vessel for causing the latter to support said uppermost weight part whereby the lowermost only of the two weight parts may control the valve for maintaining a predetermined pressure within the vessel or out of con- 11 tact with the vessel for causing the lowermost of the two weight parts to support the uppermost whereby both weight parts may control the valve for maintaining a higher predetermined pressure within the vessel.

16. A pressure vessel according to claim 14 in which the manually operated mechanism comprises a part carried by the first weight part adapted to be selectively adjusted into contact with the vessel for causing the latter to support said first weight part whereby the second weight part only of the two weight parts may control the valve for maintaining a predetermined pressure within the vessel or out of contact with the vessel for causing said first weight part to be supported by said second weight part whereby both of said weight parts may control the valve for maintaining a higher predetermined pressure within the vessel.

17. A pressure vessel provided with a vent opening, a valve for said opening adapted to be urged toward open position by pressure Within the vessel, a weight for urging said valve toward closed position, which weight comprises an upper weight part having spaced downwardly projecting portions pivotally connected to the vessel for mounting said upper weight part for swinging movement, and a second weight part having a portion between said downwardly projecting ortions and pivotally connected thereto for swingably mounting said second weightpart on said upper weight part, and a manually adjustable part carried by said upper weight part having a position of adjustment relative to said upper weight part in which it contacts with said vessel for causing the latter to support said upper weight part whereby to cause said second weight part only of the two weight parts to control the valve for maintaining a predetermined pressure within the vessel, said adjustable part having an other position of adjustment relative to said upper weight part in which it i out of contact with the vessel for causing said upper weight part to be supported by said second weight part whereby both weight parts may control said valve for maintaining a higher predetermined pressure within the vessel.

ROLAND T. SPENCER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,474,192 Gessler Nov. 13, 1923 2,297,378 Wittenberg Sept. 29, 19 2 

